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Disabling glow plugs...
Posted: Tue Nov 13, 2012 10:47 am
by tigger
So my old diesel Bongo has decided it doesn't like starting in the mornings, never a problem before, it's probably the glow plugs.
Until I get a chance to change them, I may have call to use a squirt or two of the Easy Start can. Now I know, I know, misuse it and it'll ruin an engine, but I'm going to be careful and hope only to use it once or twice as an emergency measure. Question is - I want to make sure any remaining glow plugs that still work are not glowing when the ether spray gets sucked in, to avoid any premature bangs. So how do I disable them? I was thinking maybe remove the 10amp 'glow plug' fuse in the cabin fuse box? Or can I just start cranking straight away (rather than wait for 2-3 seconds for the orange light to come on and then go out) and introduce the spray while it's cranking?
On a related note and to save me messing about in the dark and wet later - where is the air intake? Am I right in thinking it's at the front, bottom right as you look at the front of the van?
Finally - any other tips for starting reluctant Bongos?
Cheers
Dom
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:05 am
by teenmal
tigger wrote:So my old diesel Bongo has decided it doesn't like starting in the mornings, never a problem before, it's probably the glow plugs.
Until I get a chance to change them, I may have call to use a squirt or two of the Easy Start can. Now I know, I know, misuse it and it'll ruin an engine, but I'm going to be careful and hope only to use it once or twice as an emergency measure. Question is - I want to make sure any remaining glow plugs that still work are not glowing when the ether spray gets sucked in, to avoid any premature bangs. So how do I disable them? I was thinking maybe remove the 10amp 'glow plug' fuse in the cabin fuse box? Or can I just start cranking straight away (rather than wait for 2-3 seconds for the orange light to come on and then go out) and introduce the spray while it's cranking?
On a related note and to save me messing about in the dark and wet later - where is the air intake? Am I right in thinking it's at the front, bottom right as you look at the front of the van?
Finally - any other tips for starting reluctant Bongos?
Have you ever tried Body Deodorant.?
Cheers
Dom
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:09 am
by Driver+Passengers
Removing a fuse for the glowplugs sounds like your best bet if you're definitely trying to disable them. There is a rail connecting the tops of all four glowplugs and a ring terminal bolted on somewhere near the second plug. You could unbolt this terminal and insulate it to disable the glowplugs, but removing a fuse sounds like a better idea.
The glowplugs are typically active for 15 seconds if the engine is cold. The glowplug light going out means nothing. Listen for the glow plug relay clicking - you should hear two relays as you turn the key to position II, and the glowplug relay clicking off 15 seconds later.
Air intake is behind the driver's side headlight in the front.
Can't offer you any more advice on starting, never used the cans, but hope some of this helps. Suggest you do glowplugs ASAP.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:16 am
by Northern Bongolow
take off the 10mm nut that holds the voltage supply to the glow plug rail, make sure you insulate it because it may still be live when the key is on.
just one thing to think of though. i was recently changing a set and couldnt get them out as they were very tight, i stripped off all the solenoids and removed the earths on the inlet manifold for the pump etc, then i thought i would warm the engine a little to help remove them. the starter system was disabled via the pump so nothing would work, it maybe that the system is linked via the ecu so take care.
an alternative maybe to remove the fuseable link on the positive battery terminal, this is a (fuse) that supplies the plugs.
do a search on here for fuseable link.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:32 am
by tigger
Thanks guys. Northern B - there's no doubt that removing the glowplug fuse would be the easiest thing to do from an 'I have to get to work asap, no time for mucking about' perspective. But do you not think this would be an appropriate solution to disable them?
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:34 am
by Driver+Passengers
If you know which fuse it is, probably - if not, removing and isolating the supply lead from the rail might be "easier".
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:42 am
by teenmal
Why disable the glow plugs,the poor auld thing requires all the help it can get in there chilly days.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:44 am
by Diplomat
From my experience, you will eventually start even if only one glow plug still works, as long as you have enough cranking Ampere hours. You may well end up having to order a new starter motor contact set a bit sooner, though.
I only had to resort to Easy Start when they had all gone phut.
The Easy start is going to make an awful racket anyway and should encourage you to get the replacements in ASAP.
Frank
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:45 am
by Driver+Passengers
If the glowplugs are hot, will a volatile spray/vapour not ignite as it's going in, rather than when it's being compressed along with the air/fuel mix? In my mind, if that's what would happen, that sounds bad. I don't know really know anything about this, though.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 11:47 am
by mikeWalsall
teenmal wrote:tigger wrote:
Finally - any other tips for starting reluctant Bongos?
Have you ever tried Body Deodorant.?
Cheers
Dom
I often use Fly spray / deodorant / or any clean butane propellant sprays to test for air leaks around carbs / manifolds / reed valve blocks etc: on motor bike / scooters ..
If there is an air leak, the butane gets 'sucked into the engine and there is a distinct change in engine noise ..
WD 40 tends not to be so good as it uses a none volatile propellent it is just the 'white spirit' content that ignites
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 12:12 pm
by g8dhe
The 10 Amp fuse
isn't for powering the Glowplugs at all! Its merely the signal into the ECU to tell it that the Glowplugs are powered up, as normal the fuse is present merely to protect the wire from the glowplug busbar from bursting into flames if it should be shorted to earth. The exact effect of taking the fuse out I'm not sure, it may effect the timing (via the ECU) of how long the plugs still lit.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 12:19 pm
by Northern Bongolow
thanks geoff, put much better than i ever could. as usual.
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 12:29 pm
by tigger
Thanks everyone, I'll try removing the fuse first (I know which one it is) and see what happens...
(Update - no I won't after the last two posts - thanks guys!)
The reason for disabling any remaining healthy glow plugs before using easy start is that it says to do so on the can. Makes sense - as has been pointed out here, you don't want highly explosive mixture hitting a hot plug at the wrong stage in the cycle.
As for other volatiles suggested - I'm sure they work too. I did look longingly at a can of brake cleaner spray last night... But easy start does claim to have upper cylinder lubricants in it, and I guess I might as well use the right tool for the job (I have heard though that butane gas works very well and is quite benign to the engine).
And Diplomat - you're right. It does seem to get there in the end without spray. But it's a case of holding your nerve as the life gets sucked out of the battery (fortunately a newish Bosch). And it's not ideal to crank it and crank it , then take it on a pretty short journey before stopping again - which cricumstances require me to do at the moment.
Hopefully those new glow plugs will sort it asap!
Dom
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 2:05 pm
by the laird
Please don't start the use of easy start!trust me I've been in the trade a long time and believe me if you value you engine you won't use it and get glow plugs in now.would you go out in snow with no footwear on?just a wee comparison I know it's different bout I've seen the aftermath of ether being used in all types of engines,please please avoid this stuff as far as I'm concerned it shouldn't be sold!
Re: Disabling glow plugs...
Posted: Tue Nov 13, 2012 2:57 pm
by tigger
Ho ho, cheers laird, not many mechanics like the stuff do they. It'll only be a little squirt if I use it, and then following all the instructions on the can. The glow plugs should be done by the weekend. If my engine dies of ether poisoning (detonation) then oh well, I think my bongo is nearing the end of its long and happy journey anyway...
Thanks for the advice though. For anyone reading this, my own reasearch elsewhere suggests that it's probably very sound advice too - ether is OK for ancient tractor engines, much less so for modern (ish) turbo-diesels. I believe the RAC have banned their patrols from using it. But it does say 'all engines' on the can...